1 eV吸收带边GaInAs/GaNAs超晶格太阳能电池的阱层设计

使用In, N分离的GaInAs/GaNAs超晶格作为有源区是实现高质量1eV带隙 GaInNAs基太阳能电池的重要方案之一. 为在实验上生长出高质量相应吸收带边的超晶格结构, 本文采用计算超晶格电子态常用的Kronig-Penney模型比较了不同阱层材料选择下, 吸收带边为1 eV的GaInAs/GaNAs超晶格相关参数的对应关系以及超晶格应变状态. 结果表明: GaNAs与GaInAs作为超晶格阱层材料在实现1 eV的吸收带边时具有不同的考虑和要求; 在固定1 eV的吸收带边时, GaNAs材料作为阱层可获得较好的超晶格应变补偿, 将有利于生长高质量且充分吸收的太阳能电池有源区. 关键词： GaInAs/GaNAs超晶格 Kronig-Penney模型 太阳能电池

Well layer design for 1eV absorption band edge of GaInAs/GaNAs super-lattice solar cell

The GaInAs/GaNAs super-lattice with a feature of space separation of In and N constituents as an active region, is one of the most important ways to achieve 1 eV GaInNAs-based solar cells. To experimentally realize the high-quality super-lattice structure with the required band-gap, Kronig-Penney model is used to obtain the barrier thickness dependence on the well thickness and its composition. Meanwhile, the strain state of GaInAs/GaNAs SLs with various well choices is also discussed. Results show that when both the GaNAs and GaInAs act as the well layers the super-lattice can achieve 1 eV band-gap, and when the GaN_0.04As_0.96 is considered to act as the well layer, the entire GaInAs/GaNAs SLs have smaller strain accumulations as compared with the case of Ga_0.7In_0.3As as the well layer in the super-lattice structure.
Keywords： GaInAs/GaNAs super-lattice Kronig-Penney model solar cell